OBJECTIVE: To explore the genetic variants and phenotypic characteristics of patients with Neurofibromatosis type I (NF1). METHODS: Twenty two NF1 patients who presented at Enze Medical (Center) Group in Taizhou between 2018 and 2024 were selected as the study subjects. Clinical phenotype and family history were collected for the patients. Whole exome sequencing (WES) was carried out for the 22 probands to screen the variants of NF1 gene. Candidate variants were verified by Sanger sequencing of their family members. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: K20230902). RESULTS: The 22 probands were diagnosed between the age of 5 months to 47 years old, and have all shown cafe au lait spots on their skin. Seventeen patients exhibited the phenotype at birth, and 11 had various degrees of neurofibromatosis. Among them, probands 1 and 13 underwent surgical resection of the tumor but had recurred, while proband 12 had amputation due to the huge size and serious impact of the neurofibroma and had no recurrence. Five patients had various degrees of scoliosis. In total 22 germline mutations and one somatic mutation were identified among the 22 families, with 5 variants unreported previously, including 1 nonsense mutation c.1603C>T (Q535*), 3 frameshift mutations [c.7268_7269delCA (Thr2423fs), c.2293del (Arg765Alafs*26), and c.5433_5438delinsGC (Phe1812ArgfsTer50)], and 1 deletion involving exons 41-44 of the NF1 gene and adjacent introns. Proband 13 was found to harbor germline mutation c.6796C>T (Gln2266Ter) and somatic mutation c.1019_1020del (Ser340Cysfs Ter12) in the peripheral blood and tumor tissue, respectively. Among the 22 NF1 probands, 6 had received treatment due to severe illness. Proband 1 had tumor resection in the right upper limb, but was found to have malignant lung tumor and died during follow-up. Proband 12 had multiple recurrence of neurofibroma in the left ring finger. Proband 4 underwent spinal correction surgery due to severe scoliosis. Proband 11 had died due to a central nervous system disease. Among the 22 germline mutations, 6 had led to the occurrence of truncated proteins, which may have a more severe impact on the phenotype. CONCLUSION This study investigated the genetic variants and clinical phenotypes of 22 NF1 families and identified 5 novel variants of the NF1 gene, which has expanded the genotypic and phenotypic spectra of the NF1. Preliminary studies have identified an association between truncated mutations, young age, and severe phenotypes, which may provide important clues for prognosis evaluation. For the clinical diagnosis and treatment of NF1, it is necessary to consider the phenotypic characteristics and genetic testing in combination with genetic counseling and long-term follow-up.
Humans ; Neurofibromatosis 1/pathology* ; Male ; Female ; Pedigree ; Adult ; Child ; Child, Preschool ; Middle Aged ; Adolescent ; Infant ; Young Adult ; Neurofibromin 1/genetics* ; Phenotype ; Asian People/genetics* ; Mutation ; Exome Sequencing ; East Asian People

OBJECTIVE: To explore the clinical characteristics and genetic etiology of a child with Neurofibromatosis-Noonan syndrome (NFNS). METHODS: A child with NFNS who was treated at the Department of Endocrinology of Hangzhou Children's Hospital in January 2024 was selected as the study subject. Clinical data of the child was collected by retrospective analysis. Peripheral venous blood samples (2 mL each) were collected from the child and his parents. Genomic DNA was extracted, and trio-whole exome sequencing (Trio-WES) of the family was carried out. Sanger sequencing was used to perform family verification on the candidate variants. The identified variants were classified for pathogenicity according to the Standards and Guidelines for the Interpretation of Sequence Variants established by the American College of Medical Genetics and Genomics (ACMG) (hereafter referred to as the "ACMG guidelines"). This study has been approved by the Medical Ethics Committee of Hangzhou Children's Hospital (Ethics No. 2021-06). RESULTS: The child was a 7-year and 4-month-old male. He has short stature, numerous café-au-lait spots on the neck and trunk, and special facial features such as a full forehead, wide interpupillary distance, a low nasal bridge, and low-set ears. The results of Trio-WES showed that the he had harbored the NF1 gene c.3773G>T (p.W1258L) mutation, which was verified by Sanger sequencing to be de novo in origin. The NF1 gene was associated with NFNS, which has an autosomal dominant inheritance. According to the ACMG guidelines, this variant was judged to be a likely pathogenic variant (PS2+PM2+PP3+PP2). No pathogenic variant in genes associated with Noonan syndrome, such as PTPN11, SOS1, RAF1, RIT1, and KRAS, was found. CONCLUSION The child with NFNS has clinical features such as short stature, special facial features, and café-au-lait spots. The c.3773G>T (p.W1258L) variation in the NF1 gene may be the genetic etiology of the NFNS child in this study. The results of this study has enriched the variation spectrum of the NF1 gene.
Child ; Humans ; Male ; Exome Sequencing ; Mutation ; Neurofibromatosis 1/genetics* ; Neurofibromin 1/genetics* ; Noonan Syndrome/genetics*

OBJECTIVE: To summarize the gene therapy strategies for neurofibromatosis type 1 (NF1) and related research progress. METHODS: The recent literature on gene therapy for NF1 at home and abroad was reviewed. The structure and function of the NF1 gene and its mutations were analyzed, and the current status as well as future prospects of the transgenic therapy and gene editing strategies were summarized. RESULTS: NF1 is an autosomal dominantly inherited tumor predisposition syndrome caused by mutations in the NF1 tumor suppressor gene, which impair the function of the neurofibromin and lead to the disease. It has complex clinical manifestations and is not yet curable. Gene therapy strategies for NF1 are still in the research and development stage. Existing studies on the transgenic therapy for NF1 have mainly focused on the construction and expression of the GTPase-activating protein-related domain in cells that lack of functional neurofibromin, confirming the feasibility of the transgenic therapy for NF1. Future research may focus on split adeno-associated virus (AAV) gene delivery, oversized AAV gene delivery, and the development of new vectors for targeted delivery of full-length NF1 cDNA. In addition, the gene editing tools of the new generation have great potential to treat monogenic genetic diseases such as NF1, but need to be further validated in terms of efficiency and safety. CONCLUSION Gene therapy, including both the transgenic therapy and gene editing, is expected to become an important new therapeutic approach for NF1 patients.
Humans ; Neurofibromatosis 1/pathology* ; Neurofibromin 1/metabolism* ; GTPase-Activating Proteins ; Mutation ; Genetic Predisposition to Disease ; Genetic Therapy

Cardiovascular System/pathology* ; Constriction, Pathologic/genetics* ; Point Mutation ; Neurofibromin 1/genetics* ; Animals ; Mice

OBJECTIVE: To explore the molecular basis for a Chinese family affected with neurofibromatosis type I. METHODS: Peripheral blood samples were collected from the proband and his parents. Potential mutations of NF1 gene were screened by PCR and Sanger sequencing. Pathogenicity of candidate mutations was analyzed using Polyphen-2 and Provean software. RESULTS: Two mutations of the NF1 gene, including c.702G>A (synonymous mutation) and c.1733T>G (missense mutation), were discovered in the proband. Neither mutation was found in his parents and 50 healthy controls. Bioinformatics analysis indicated that the c.1733T>G mutation (p.Leu578Arg) was probably damaging. The affected codon L578 is highly conserved across various species. CONCLUSION The c.1733T>C mutation of the NF1 gene probably underlies the neurofibromatosis type I in this family.
Asian Continental Ancestry Group ; Genes, Neurofibromatosis 1 ; Humans ; Mutation ; Neurofibromatosis 1 ; genetics ; Neurofibromin 1 ; genetics ; Pedigree

Neurofibromatosis type 1 (NF1) is a common neurocutaneous syndrome that presents with multiple café-au-lait spots, skinfold freckling, dermatofibromas, neurofibromas, and Lisch nodules. Mutations of the NF1 gene, encoding the protein neurofibromin, have been identified as the cause of this disease. NF1 can also present with precocious puberty and be associated with optic pathway tumors. Hypothalamic hamartoma as the cause of precocious puberty in patients with NF1 has been rarely described in the literature. Here, we report the findings for a patient with NF1 and precocious puberty associated with a hypothalamic hamartoma who had a newly discovered 14-bp deletion mutation in exon 5 of NF1. To our knowledge, this is the first time this combination is reported in the literature.
Adolescent ; Child* ; Exons ; Genes, Neurofibromatosis 1 ; Hamartoma* ; Histiocytoma, Benign Fibrous ; Humans ; Hypothalamic Diseases ; Neurocutaneous Syndromes ; Neurofibroma ; Neurofibromatoses* ; Neurofibromatosis 1* ; Neurofibromin 1 ; Puberty ; Puberty, Precocious* ; Sequence Deletion

Neurofibromatosis type 1 (NF-1) is an autosomal dominant neurocutaneous syndrome caused by mutations in the neurofibromin gene. NF-1 patients have a high risk of tumors, and optic glioma is the most commonly observed central nervous system tumor in these patients. However, glioblastoma is extremely rare in pediatric NF-1 patients. Here we report the discovery of a novel heterozygous c.6766_6767insAA (p.Ser2256Lysfs*4), pathogenic mutation in the neurofibromin gene in a 17-year-old boy with NF-1-associated glioblastoma.
Adolescent ; Central Nervous System ; Glioblastoma* ; Humans ; Male ; Neurocutaneous Syndromes ; Neurofibromatoses* ; Neurofibromatosis 1 ; Neurofibromin 1* ; Optic Nerve Glioma

Ependymomas occur in both the brain and spine. The prognosis of these tumors sometimes differs for different locations. The genetic landscape of ependymoma is very heterogeneous despite the similarity of histopathologic findings. In this review, we describe the genetic differences between spinal ependymomas and their intracranial counterparts to better understand their prognosis. From the literature review, many studies have reported that spinal cord ependymoma might be associated with NF2 mutation, NEFL overexpression, Merlin loss, and 9q gain. In myxopapillary ependymoma, NEFL and HOXB13 overexpression were reported to be associated. Prior studies have identified HIC-1 methylation, 4.1B deletion, and 4.1R loss as common features in intracranial ependymoma. Supratentorial ependymoma is usually characterized by NOTCH-1 mutation and p75 expression. TNC mutation, no hypermethylation of RASSF1A, and GFAP/NeuN expression may be diagnostic clues of posterior fossa ependymoma. Although MEN1, TP53, and PTEN mutations are rarely reported in ependymoma, they may be related to a poor prognosis, such as recurrence or metastasis. Spinal ependymoma has been found to be quite different from intracranial ependymoma in genetic studies, and the favorable prognosis in spinal ependymoma may be the result of the genetic differences. A more detailed understanding of these various genetic aberrations may enable the identification of more specific prognostic markers as well as the development of customized targeted therapies.
Brain ; Ependymoma* ; Genetic Research* ; Genetics ; Methylation ; Multiple Endocrine Neoplasia Type 1 ; Neoplasm Metastasis ; Neurofibromin 2 ; Prognosis ; Recurrence ; Spinal Cord ; Spine

OBJECTIVETo report on two children manifesting multiple cafe-au-lait spots suspected as neurofibromatosis type 1, and perform NF1 gene mutation analysis.

METHODSBlood samples were collected from the 2 children, their unaffected parents and 100 normal controls. The entire coding region of the NF1 gene was amplified by PCR and subjected to direct sequencing.

RESULTSIn patient 1, a novel frameshift mutation c.1948delT (p.Leu650TyrfsX38) was identified in exon 12 of the NF1 gene. And in patient 2, a previously reported nonsense mutation c.541C>T (p.Gln181X) was revealed in exon 4b. The same mutations were not detected in their unaffected parents or 100 normal controls.

CONCLUSIONThe two patients were diagnosed with neurofibromatosis type 1 by molecular genetic testing. The pathogenic mutations were c.1948delT and c.541C>T, respectively.

Adult ; Base Sequence ; Exons ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Neurofibromatosis 1 ; genetics ; Neurofibromin 1 ; genetics ; Point Mutation

No abstract available.
Neurofibromatoses* ; Neurofibromatosis 1* ; Neurofibromin 1 ; Vitiligo*